<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
      title="黑马头条"
      @click-left="onClickLeft"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div v-if="loading" class="loading-wrap">
        <van-loading
          color="#3296fa"
          vertical
        >加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">{{ article.pubdate | relativeTime }}</div>

          <!-- 子传父 $event 就是事件参数 -->
          <!-- <follow-user
            class="follow-btn"
            :is-followed = 'article.is_followed'
            :user-id="article.aut_id"
            @update-is_followed = 'article.is_followed = $event'
           ></follow-user> -->

          <!-- 
            当我们传给子组件的数据既要使用还要修改
              传递： props
                    :is-followed = 'article.is_followed'
              修改：自定义事件
                    @update-is_followed = 'article.is_followed = $event'
            
            简写方式：在组件上使用 v-model
              相当于：
                value='article.is_followed'
                @input='article.is_followed = $event'
              value 和 @input 是固定写法

            如果需要修改 v-model 的规则名称，可以通过子组件的 model 来配置修改（vue.js文档-教程-深入了解组件-自定义事件）

            一个组件上只能使用一次 v-model
            如果有多个数据需要实现类似于 v-model 的效果，咋办？
            可以使用属性的 .sync 修饰符（vue.js文档-教程-深入了解组件-sync修饰符）
           -->
           <follow-user
            class="follow-btn"
            v-model = 'article.is_followed'
            :user-id="article.aut_id"
           ></follow-user>

          <!-- <van-button
            v-if="article.is_followed"
            class="follow-btn"
            round
            size="small"
            :loading="followLoading"
            @click="onFollow"
          >已关注</van-button>
          <van-button
            v-else
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
            :loading="followLoading"
            @click="onFollow"
          >关注</van-button> -->

        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div 
          class="article-content markdown-body " 
          v-html="article.content"
          ref="article-content"
        ></div>
        <van-divider>正文结束</van-divider>

        <!-- 文章评论列表 -->
        <comment-list
          :source = 'article.art_id'
          :list="commentList"
          @updateList="commentList.push(...$event)"
          @onload-success="totalCommentCount = $event.total_count"
          @reply-click="onReplyClick"
        />
        <!-- /文章评论列表 -->

        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button
            class="comment-btn"
            type="default"
            round
            size="small"
            @click="isPostShow = true"
          >写评论</van-button>
          <van-icon
            name="comment-o"
            :info="totalCommentCount"
            color="#777"
          />
          <!-- <van-icon
            color="#777"
            name="star-o"
          /> -->
          <!-- 收藏按钮 -->
          <CollectArticle 
            v-model='article.is_collected' 
            :articleId = 'article.art_id'
          />
          

          <!-- <van-icon
            color="#777"
            name="good-job-o"
          /> -->
          <!-- 点赞按钮 -->
          <LikeArticle
            v-model='article.attitude' 
            :articleId = 'article.art_id'
          />
          <van-icon name="share" color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->

        <!-- 发布评论 -->
        <van-popup 
          v-model="isPostShow" 
          position="bottom" 
        >
          <CommentPost
            :target="article.art_id"
            @post-success = 'onPostSuccess'
          />
        </van-popup>
        <!-- /发布评论 -->

      </div>
      <!-- /加载完成-文章详情 -->

    
      <!-- 加载失败：404 -->
      <div v-else-if="errStatus === 404" class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button 
          class="retry-btn" 
          @click="loadArticle"
        >点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 评论回复 -->
    <!-- 
      弹出层是懒渲染的： 只有在第一次展示的时候才会渲染里面的内容，之后它的关闭和显示都是在切换内容的显示和隐藏
     -->
    <van-popup 
      v-model="isReplyShow" 
      position="bottom" 
      style="height: 100%;"
    >
     <!-- 
      v-if 条件渲染
      true: 渲染元素节点
      false：不渲染
      -->
      <CommentReply
        v-if="isReplyShow"
        :comment="currentComment"
        @updateReplyCount="currentComment.reply_count++"
        @close="isReplyShow = false"
      />
    </van-popup>
    <!-- /评论回复 -->


  </div>
  
</template>

<script>
import { getArticlesById } from '@/api/article'
import { ImagePreview } from 'vant';
// import { addFollow ,deleteFollow } from '@/api/user'
// import follow-user from '@/components/follow-user'
import FollowUser from '@/components/follow-user/index.vue';
import CollectArticle from '@/components/collect-article';
import LikeArticle from '@/components/like-article';
import CommentList from './components/comment-list'
import CommentPost from './components/comment-post.vue'
import CommentReply from './components/comment-reply.vue'

// ImagePreview({
//   images: [
//     'https://img01.yzcdn.cn/vant/apple-1.jpg',
//     'https://img01.yzcdn.cn/vant/apple-2.jpg',
//   ],
//   // 起始位置,从 0 开始
//   startPosition: 1,
//   onClose() {
//     console.log('close');
//   }
// });


export default {
  name: 'ArticleIndex',
  // 原本我们要获得 articleId 的值得去 router 里面去找
  // 在路由中设置 props: true 。通过这种方式可以简化我们在组件中获取 articleId 参数。以及实现对路由参数的解耦：就是我们可以在别的组件通过 父传子 等方式来 使用 articleId
  props: {
    articleId: {
      type: [Number, String, Object],
      required: true
    }
  },
  // 给所有的后代组件提供数据
  provide: function () {
    return {
      articleId: this.articleId
    }
  },
  data() {
    return {
      article: {} , //文章的内容
      loading : true, //加载中的loading状态
      errStatus: 0 ,//失败状态码
      // followLoading:false
      totalCommentCount: 0 ,// 评论总数量
      isPostShow: false,  //控制发布评论的显示状态
      commentList: [] ,//评论列表
      isReplyShow: false, // 回复评论弹出层的显示状态
      currentComment: {}  // 当前点击回复的评论项
    }
  },
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply
  },
  created () {
    this.loadArticle()
  },
  methods: {
    async loadArticle() {
      this.loading = true
      try {
        const { data: { data } } = await getArticlesById(this.articleId)
        // console.log(data);

        // if (Math.random() > 0.5) {
        //   JSON.parse('agsdfhgapwo')
        // }

        // 数据驱动视图这件事不是立即的
        this.article = data

        // 初始化图片，点击预览
        // console.log(this.$refs['article-content']);  // 所以 undefined
        setTimeout(() => {
          // console.log(this.$refs['article-content']);
          this.previewImage()
        },0)

        // 请求成功，关闭loading
        // this.loading = false
      } catch (err) {
        if (err.response && err.response.status === 404) {
          this.errStatus = 404
        } 
        // 请求失败，关闭loading
        // this.loading = false
        console.log('获取数据失败',err);
      }

      // 无论成功还是失败，都需要关闭loading
      this.loading = false
    },
    onClickLeft() {
      this.$router.back()
    },
    previewImage() {
      //  得到所有的 img 节点
      const articleContent = this.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')
      // console.log(imgs);

      //获取所有 img 地址 
      const images = []

      imgs.forEach((img, index )=> {
        images.push(img.src)
        // 给每个 img 注册点击事件，在处理函数中调用预览函数
        img.onclick = () => {
          ImagePreview({
            // 预览的图片地址数组
            images,
            // 起始位置，从 0 开始
            startPosition: index,
          });
        }
      });
      // console.log(images);
    },
    onPostSuccess(data) {
      // 关闭弹出层
      this.isPostShow = false
      // 将发布内容显示到列表顶部
      this.commentList.unshift(data.new_obj)
    },

    onReplyClick(comment) {
      // console.log(comment);
      this.currentComment = comment

      // 显示评论回复弹出层
      this.isReplyShow = true
    },

/*     async onFollow() {
      this.followLoading = true //展示关注按钮的 loading 状态
      try {
        if (this.article.is_followed) {
          // 已关注，取消关注
          await deleteFollow(parseInt(this.article.aut_id))
        } else {
          // 未关注，添加关注
          await addFollow(parseInt(this.article.aut_id))
        }
        // 更新视图状态
        this.article.is_followed = !this.article.is_followed
      } catch (err) {
        let message = '操作失败，请重试！'
        if (err.response && err.response.status === 400) {
          message = '你不能关注你自己！'
        }
        this.$toast(message)
      }
      this.followLoading = false //展示感知按钮的 loading 状态
    } */
  }
}
</script>

<style scoped lang="less">
@import "./github-markdown.css";

  .article-container {
    .main-wrap {
      position: fixed;
      left: 0;
      right: 0;
      top: 92px;
      bottom: 88px;
      overflow-y: scroll;
      background-color: #fff;
    }
    .article-detail {
      .article-title {
        font-size: 40px;
        padding: 50px 32px;
        margin: 0;
        color: #3a3a3a;
      }
  
      .user-info {
        padding: 0 32px;
        .avatar {
          width: 70px;
          height: 70px;
          margin-right: 17px;
        }
        .van-cell__label {
          margin-top: 0;
        }
        .user-name {
          font-size: 24px;
          color: #3a3a3a;
        }
        .publish-date {
          font-size: 23px;
          color: #b7b7b7;
        }
        .follow-btn {
          width: 170px;
          height: 58px;
        }
      }
  
      .article-content {
        padding: 55px 32px;
        /deep/ p {
          text-align: justify;
        }
      }
    }
  
    .loading-wrap {
      padding: 200px 32px;
      display: flex;
      align-items: center;
      justify-content: center;
      background-color: #fff;
    }
  
    .error-wrap {
      padding: 200px 32px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      background-color: #fff;
      .van-icon {
        font-size: 122px;
        color: #b4b4b4;
      }
      .text {
        font-size: 30px;
        color: #666666;
        margin: 33px 0 46px;
      }
      .retry-btn {
        width: 280px;
        height: 70px;
        line-height: 70px;
        border: 1px solid #c3c3c3;
        font-size: 30px;
        color: #666666;
      }
    }
  
    .article-bottom {
      position: fixed;
      left: 0;
      right: 0;
      bottom: 0;
      display: flex;
      justify-content: space-around;
      align-items: center;
      box-sizing: border-box;
      height: 88px;
      border-top: 1px solid #d8d8d8;
      background-color: #fff;
      .comment-btn {
        width: 282px;
        height: 46px;
        border: 2px solid #eeeeee;
        font-size: 30px;
        line-height: 46px;
        color: #a7a7a7;
      }
      .van-icon {
        font-size: 40px;
        .van-info {
          font-size: 16px;
          background-color: #e22829;
        }
      }
    }
  }
  </style>